Sofa



FIG. 1 is a perspective view of our new design for a sofa;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a back elevational view thereof;

FIG. 4 is a right elevational side view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a left elevational view thereof;

FIG. 7 is a top plan view of a sofa showing a second embodiment of the design shown in FIG. 1; and,

FIG. 8 is a top plan view of a sofa showing a third embodiment of the design shown in FIG. 1.

The broken lines showing is included for the purpose of illustrating environment and forms no part of the claimed design. 

CLAIM The ornamental design for a sofa, as shown and described. 